Police have refused to issue a permit allowing a march in the city tomorrow that organisers claim will be peaceful, ahead of Friday's World Trade Organisation meeting in Sydney.

Protesters will demonstrate outside the talks at Sydney Olympic Park but several groups, including unions, churches and environmental groups, had planned a rally in the city.

The NSW Police Assistant Commissioner, Dick Adams, said the decision had been taken "because of the threats of violence emanating from an extreme element among protest groups".

"It's my responsibility to ensure the safety of the international visitors, the general public, the police and the protesters themselves," Mr Adams said.

But many of the groups involved said tomorrow's peaceful march would go ahead, accusing the police of taking away their right to freedom of expression.");document.write("

advertisement

");
}
}
// -->

A board member of the international aid monitoring group Aidwatch, James Arvanitakis, said police were inviting conflict by not allowing the protest to go ahead legally.

"The only way the protests will get out of control is if police try and stop it," Mr Arvanitakis said.

He called on the NSW Police Minister, Michael Costa, to guarantee that police actions would be peaceful.

Hundreds of police are expected to be in the city tomorrow for the marches.

A march through the city this evening run by the refugee advocacy group Free Movement of People also plans to go ahead without a permit.

Greenpeace, the Construction Forestry Mining and Energy Union, the National Union of Students, some churches, socialist youth group Resistance, the Greens and the Australian Democrats will participate in several different marches tomorrow that plan to meet in Hyde Park for a rally at noon.

A strong police presence is also planned for Friday when 25 of the world's trade ministers will discuss the Doha round of trade talks at the Novotel hotel at Olympic Park where discussion will centre around the removal of trade barriers for agriculture and services.

Mr Adams said police would not tolerate any violent outbursts but were encouraging people to protest "peacefully and lawfully".

Olympic Park has been turned into a virtual exclusion zone with the train station closed, businesses temporarily closed and security on entry points. The crackdown will also disrupt marking for the HSC with the Board of Studies main centre at Homebush affected by the no-go zone.

About three kilometres of perimeter fencing has been erected and people entering the area can be searched under powers given to police under the extensive Sydney Olympic Park Act.

Protesters will be corralled into two "passive protest areas" near the Novotel hotel, but they are concerned they will be without shade, running water or toilets.

"It seems that the police want to provoke a reaction from protesters by making it impossible for people to remain in a passive and peaceful demonstration," said Jim Casey, an organiser with the Direction Action Collective.

Protesters have also been banned from using placards or banners or public service announcement systems. "It's an empty right to protest if you can't express yourself," Mr Casey said.

Greens MLC Ian Cohen said "hardline policing at the WTO will create images of conflict that strengthen the Government's lead in the polls".

"The Government will then use this to justify bringing in terrorism policing laws which are even more draconian."